// Copyright 2022 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include "VideoBackends/Metal/MTLVertexManager.h"

#include "VideoBackends/Metal/MTLStateTracker.h"

#include "VideoCommon/PixelShaderManager.h"
#include "VideoCommon/Statistics.h"
#include "VideoCommon/VertexShaderManager.h"

Metal::VertexManager::VertexManager()
{
}

Metal::VertexManager::~VertexManager() = default;

void Metal::VertexManager::UploadUtilityUniforms(const void* uniforms, u32 uniforms_size)
{
  g_state_tracker->SetUtilityUniform(uniforms, uniforms_size);
}

bool Metal::VertexManager::UploadTexelBuffer(const void* data, u32 data_size,
                                             TexelBufferFormat format, u32* out_offset)
{
  *out_offset = 0;
  StateTracker::Map map = g_state_tracker->Allocate(StateTracker::UploadBuffer::Texels, data_size,
                                                    StateTracker::AlignMask::Other);
  memcpy(map.cpu_buffer, data, data_size);
  g_state_tracker->SetTexelBuffer(map.gpu_buffer, map.gpu_offset, 0);
  return true;
}

bool Metal::VertexManager::UploadTexelBuffer(const void* data, u32 data_size,
                                             TexelBufferFormat format, u32* out_offset,
                                             const void* palette_data, u32 palette_size,
                                             TexelBufferFormat palette_format,
                                             u32* out_palette_offset)
{
  *out_offset = 0;
  *out_palette_offset = 0;

  const u32 aligned_data_size = g_state_tracker->Align(data_size, StateTracker::AlignMask::Other);
  const u32 total_size = aligned_data_size + palette_size;
  StateTracker::Map map = g_state_tracker->Allocate(StateTracker::UploadBuffer::Texels, total_size,
                                                    StateTracker::AlignMask::Other);
  memcpy(map.cpu_buffer, data, data_size);
  memcpy(static_cast<char*>(map.cpu_buffer) + aligned_data_size, palette_data, palette_size);
  g_state_tracker->SetTexelBuffer(map.gpu_buffer, map.gpu_offset,
                                  map.gpu_offset + aligned_data_size);
  return true;
}

void Metal::VertexManager::ResetBuffer(u32 vertex_stride)
{
  const u32 max_vertex_size = 65535 * vertex_stride;
  const u32 vertex_alloc = max_vertex_size + vertex_stride - 1;  // for alignment
  auto vertex = g_state_tracker->Preallocate(StateTracker::UploadBuffer::Vertex, vertex_alloc);
  auto index =
      g_state_tracker->Preallocate(StateTracker::UploadBuffer::Index, MAXIBUFFERSIZE * sizeof(u16));

  // Align the base vertex
  m_base_vertex = (vertex.second + vertex_stride - 1) / vertex_stride;
  m_vertex_offset = m_base_vertex * vertex_stride - vertex.second;
  m_cur_buffer_pointer = m_base_buffer_pointer = static_cast<u8*>(vertex.first) + m_vertex_offset;
  m_end_buffer_pointer = m_base_buffer_pointer + max_vertex_size;
  m_index_generator.Start(static_cast<u16*>(index.first));
}

void Metal::VertexManager::CommitBuffer(u32 num_vertices, u32 vertex_stride, u32 num_indices,
                                        u32* out_base_vertex, u32* out_base_index)
{
  const u32 vsize = num_vertices * vertex_stride + m_vertex_offset;
  const u32 isize = num_indices * sizeof(u16);
  StateTracker::Map vmap = g_state_tracker->CommitPreallocation(
      StateTracker::UploadBuffer::Vertex, vsize, StateTracker::AlignMask::None);
  StateTracker::Map imap = g_state_tracker->CommitPreallocation(
      StateTracker::UploadBuffer::Index, isize, StateTracker::AlignMask::None);

  ADDSTAT(g_stats.this_frame.bytes_vertex_streamed, vsize);
  ADDSTAT(g_stats.this_frame.bytes_index_streamed, isize);

  DEBUG_ASSERT(vmap.gpu_offset + m_vertex_offset == m_base_vertex * vertex_stride);
  g_state_tracker->SetVerticesAndIndices(vmap.gpu_buffer, imap.gpu_buffer);
  *out_base_vertex = m_base_vertex;
  *out_base_index = imap.gpu_offset / sizeof(u16);
}

void Metal::VertexManager::UploadUniforms()
{
  g_state_tracker->InvalidateUniforms(VertexShaderManager::dirty, PixelShaderManager::dirty);
  VertexShaderManager::dirty = false;
  PixelShaderManager::dirty = false;
}